Bobbin-controlling adjunct for sewing-machine shuttles



July 13 1926 1,592,235

E. J. THOMSON BOBBIN CONTRbLLING ADJUNCT FOR SEWING MACHINE SHUTTLESFiled Mar ch e, 1926 Invenfir hairs;

EDWARD J. THOMSON, OF QUINCY, MASSACHUSETTS, ASSIGNOR OEONE-HA.LF .TOROBERT N. CORTHELL, OF -AU13UE1I, MAINE;

BGBBIN:GOhlTfiQLLlIll'GiADJUllcT FOB SERVING -1VACHINE. SHUTTLES.

Application filed March 6, 1526.

This invention relates to a sewing-machine shuttlehavinga center post onwhich a dismain bobbin is rotatable and movable endwise, an annular curbsurrounding and con centric with the post,and a bobbin stop limitingoutward movement of the bobbin on the bobbin on the post.

The object of the invention is to provide a bobbin-controlling adjunctadapted to be separably engaged by friction with the internal surface ofa curb, which is not necessarily limited to a given diameter, and tocooperate with the bobbin stop in preventing loose rotation of thebobbin, and thus ensuring delivery of the thread only as required by thestitch-forming mechanism of a sewing-machine.

Of the accompanying drawings forming a part of this specification,

Figure 1 is a top plan view of a shuttle and a bobbin-controllingadjunct therein embodying the invention, the bobbin being removed.

Figure 2- is a section on line 22 of Figure 1, showing the bobbinconfined between the adjunct and the stop.

Figure 3 is a view similar to Figure 2, the stop being displaced and thebobbin removed.

Figure 4 shows the adjunct in perspective, the normal form of the shoehereinafter described being shown by full lines, and its form, whenengaged with the curb, as in Figures 1, 2 and 3, being shown by dottedlines. 7

The same reference characters indicate the same parts in all of thefigures.

In the drawings, 12 designates the center post of a wellknown type ofshuttle. 13 designates a bobbin stop formed as an arm pivoted at 14 tothe post, and 15 designates the annular curb surrounding the post andjoined to the bottom 16, to which the post is also joined.

Figure 2 shows in section a ready-wound bobbin composed of a tubularcore 17, and a universally wound thread mass 18 thereon.

The core loosely surrounds the post, so that the bobbin is rotatable andmovable enclwise on the post. The bobbin stop is adapted to standhorizontally, as shown by Figures 1 and 2, to limit the outward endwisemovement of the bobbin, and vertically as shown by Figure 3, to permitthe insertion and removal of the bobbin, the usual means Serial No.92,742.

comprises a fiexibleresilient curvedshoellt). preferably 'ofthintempered steel, adapted to conform to, and have an elongated fric tionalbearing on the internal surface of the curb. The normal curvature of theshoe,

indicated by full lines in Figure 4, is greater than that of the curb.

The adjunct comprises also a resilient pressing finger 20, preferably ofthe same material as the shoe, and preferably integral therewith. Thefinger is joined at one end to the midlengthportion of the shoe, andprojects from one side thereof, viz., the reentrant side, as shown byFigure 4. The finger has a free end portion, containing an opening 21,loosely receiving the post. Said portion has also a frictional face 22,adapted to bear on the inner end of the bobbin. The adjunct is appliedto the shuttle by increasing the curvature of the shoe, as indicated bydotted lines in Figure 1, and forcing it into the curb, until its inneredge contacts with the bottom 16. This operation tensions the shoe andcauses it to frictionally engage the internal surface of the curb withsufficient force to confine or anchor the pressing finger in itsoperative position.

The pressing finger normally stands at a' maximum distance from thebottom, 16, as shown by Figure 3, so that when the bobbin is insertedand confined by the stop 13, the pressing finger is pressed inward, andtensioned, exerts outward pressure on the bobbin, and presses the bobbinagainst the stop. Rotation of the bobbin is, therefore, resisted by thepressing finger and the stop, so that loose rotation of the bobbin ispreventedn The opening 21 is so formed that its margin cannot bind onthe post when the finger is in any position it is capable of assuming. 1

It will now be seen that the shoe may conform to curbs of differentdiameters, so that the adjunct is not limited to use with a curb of agiven diameter, and may be used with variously proportioned shuttles ofthe general type shown.

I claim:

For use with a sewing-machine shuttle which includes a central post onwhich a bobbin is rotatable and movable endwise, a bobbin stop adaptedto limit outward movement of the bobbin on the post, and 21 circularcurb concentric with the post and surrounding the bobbin-receivingspace; a bobbin-controlling adjunct comprising a flexible resilientcurved shoe, adapted to conform to, and have an elongated frictionalbearing on the inter al surface of the curb, and having a normalcurvature greater than that of said surface, and a resilient pressingfinger joined at one end to the inidlength portion of the shoe,projecting from one side thereof, and having a free end portioncontaining an opening formed. to loosel} receive the post, said portionhaving also a frictional face adapted to hear on the inner end of thebobbin and press the outer end thereof against the stop, the shoe beingadapted to be tensioned by its insertion in the curb, and conformable tocurbs of different diameters. the frictional engagement of the shoe withthe curb causing the shoe to anchor the pressing finger in the curb, inposition to cooperate with the stop in yieldingly resisting the rotationof the bobbin on the post, the pressing finger being adapted to betensioned by the insertion of a bobbin in the shuttle.

In testi1non whereof I have afiirzcd my signature.

EDVARD J. l.:lOMSOX.

